下面是最易犯错的代码：

$date_start = mktime(0, 0, 0, 1, 1, 2010);
$date_end = mktime(0, 0, 0, 4, 15, 2014);

for($tm = $date_end; $tm >= $date_start; $tm -= 86400)
{
$year = date(‘Y’, $tm);
$month = date(‘m’, $tm);
$day = date(‘d’, $tm);

echo date(‘Y-m-d H:i:s’, $tm) . “\n”;
}

下面是正确的代码：

for($tm = $date_end; $tm >= $date_start; $tm -= 40000)
{

$year = date(‘Y’, $tm);
$month = date(‘m’, $tm);
$day = date(‘d’, $tm);

echo date(‘Y-m-d H:i:s’, $tm) . “\n”;

$tm = mktime(0, 0, 0, $month, $day, $year);
}

或者下面的代码也正确：

$dt = new DateTime(’2014-04-15′);
for($dt = new DateTime(“@$date_end”); date_timestamp_get($dt) >= $date_start; $dt = date_sub($dt, date_interval_create_from_date_string(’1 day’)))
{
$tm = date_timestamp_get($dt);
$year = date(‘Y’, $tm);
$month = date(‘m’, $tm);
$day = date(‘d’, $tm);

echo date(‘Y-m-d H:i:s’, $tm) . “\n”;

$dt = new DateTime(date(‘Y-m-d 00:00:00′, $tm));
}